Isn’t (or wasn’t) Chelyabinsk the center of Russias’ famed/feared bio-weapons labs?
There is an enormous amount of important military stuff of all kinds near Chelyabinsk.
It was a city of Sverdlovsk (now Yekaterinburg) 200 miles north of Chelybinsk.
Chelyabinsk is a home for a lot of defense research and manufacturing too.
Not so much bio-weapons, but Chelyabinsk Oblast (the equivalent of a state or province) had several top-secret nuclear facilities in it.
The city itself was more famous in Russia for becoming the center of T-34 tank production during WW II. The T-34 factories were disassembled, moved from the west of the country a thousand miles east to and beyond the Urals, and reassembled. Chelyabinsk became known as “Tankograd” as a result.